This project involves a detailed study on the structure and physiological function of malic enzyme and fumarase from the parasitic roundworm Ascaris suum. The studies on the malic enzyme will involve kinetic relationships, sulfhydryl reactivity and fluorescence of the protein in the presence of various substrates and effectors. A new isolation procedure will be developed for the malic enzyme utilizing agarose-coupled Blue Dextran. The fumarase studies will involve development of a procedure to purify the enzyme to homogeneity and will further delineate the kinetics of the fumarase-malic enzyme tandem system and the effects each enzyme has on the catalytic activity of the other enzyme. In this manner, precise control mechanisms of the dismutation reaction in the mitochondria of the parasite can be studied. BIBLIOGRAPHIC REFERENCES: Supowit, S. and Harris, B. 1976. Ascaris suum hexokinase: purification and possible function in compartmentation of glucose 6-phosphate in muscle. Biochem. Biophys. Acta (In Press). Dedman, J. and Harris, B.G. 1976. Studies on the association of aldolase with agarose-bound actin. Arch. Biochem. Biophys. (In Press).